#define _POSIX_C_SOURCE 200809L

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "IO/IOBackend.h"
#include "utils/env.h"

static void _usage_xerror(void)
{
    errx(2, "Usage:\n\
    \t./42sh [--pretty-print] [FILENAME]\n\
    \t./42sh [-c | --pretty-print] [FILENAME]\n\
    \t./42sh [--pretty-print] [ < FILENAME ]");
}

static struct string *_parse_input(FILE *f)
{
    ssize_t r = 0;
    struct string *output = string_create(NULL);
    char buf[DEFAULT_RW_SIZE + 1] = { 0 };
    do
    {
        r = fread(buf, sizeof(char), DEFAULT_RW_SIZE, f);
        if (r == -1)
        {
            fprintf(stderr, "_parse_input: fread failed!");
            return NULL;
        }
        buf[r] = 0;
        string_pushstr(output, buf);
    } while (r >= DEFAULT_RW_SIZE);

    return output;
}

static void _add_newline(struct string *s)
{
    if (s->data[s->length - 1] != '\n')
    {
        string_pushc(s, '\n');
    }
}

struct string *get_input(int argc, char *argv[])
{
    int i = 1;
    bool s_input = false;
    FILE *f = NULL;
    while (i < argc && argv[i][0] == '-')
    {
        if (strcmp(argv[i], "-c") == 0)
        {
            s_input = true;
            i++;
            continue;
        }

        if (strcmp(argv[i], "--pretty-print") == 0)
        {
            env_set("PRETTY_PRINT", "TRUE");
            i++;
            continue;
        }

        _usage_xerror();
    }
    if (i == argc)
    {
        f = stdin;
    }
    else
    {
        char *input = argv[i];
        if (s_input)
        {
            f = fmemopen(input, strlen(input) + 1, "r");
        }
        else
        {
            f = fopen(input, "r");
            env_set("0", input);
        }
    }

    if (!f)
    {
        errx(2, "Invalid path!");
    }

    struct string *string_input = _parse_input(f);
    if (f != stdin)
    {
        fclose(f);
    }

    int nb_args = 0;
    i++;
    for (; i < argc; i++)
    {
        nb_args++;
        char buf[16] = { 0 };
        sprintf(buf, "%d", nb_args);
        env_set(buf, argv[i]);
    }

    char buf2[16] = { 0 };
    sprintf(buf2, "%d", (s_input && nb_args > 0) ? 1 : nb_args);
    env_set("#", buf2);

    _add_newline(string_input);
    return string_input;
}